1. Field
Embodiments relate to a scan driver and a display device including the same. More particularly, embodiments relate to a display device applied to a high resolution display panel of a large size by providing a scan driver circuit capable of driving with a high speed without usage of a CMOS transistor structure under digital driving of the display device.
2. Description of the Related Art
Various kinds of flat display devices that are capable of reducing detriments of cathode ray tubes CRT, such as their heavy weight and large size, have been developed in recent years. Such flat display devices include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic light emitting diode (OLED) displays.
Among the above flat panel displays, OLED displays using an OLED generate light by a recombination of electrons and holes for the display of images. OLED displays have a fast response speed, are simultaneously driven with low power consumption, and have excellent luminous efficiency, luminance, and viewing angle. Generally, the OLED displays are classified into passive matrix OLED (PMOLED) displays and active matrix OLED (AMOLED) displays according to a driving method of the OLED.
PMOLED displays use a method in which an anode and a cathode are formed to cross each other, and cathode lines and anode lines are selectively driven. PMOLED displays have a simple structure and a low cost. However it is difficult to realize a PMOLED displays having a large size or high accuracy.
AMOLED displays use a method in which a thin film transistor and a capacitor are integrated in each pixel and a voltage is maintained by the capacitor. AMOLED displays may be used to realize a panel of a large size and/or high accuracy. However, it is difficult to technically realize the control method thereof and AMOLED displays have a comparatively high cost.
Due to demand for improved resolution, contrast, and operation speed, the current trend is toward the AMOLED displays, in which respective unit pixels selectively are turned on or off. AMOLED displays generally include pixels arranged in a matrix format, a data driver transmitting a data signal to data lines connected to the pixels, and a scan driver transmitting a scan signal to scan lines connected to the pixels.
In an analog driving method, the scan driver selects the pixels as a line unit while sequentially supplying the scan signal every horizontal period. The data driver supplies the data signal to the selected pixels by the line unit by the scan signal. Thus, the pixels supply a predetermined current corresponding to the data signal to the OLED, thereby displaying a predetermined image corresponding to the data signal.
In a digital driving method, the AMOLED display divides one frame into a plurality of sub-frames, resulting in short scan times, which scan driver to operate at high speeds. Typically, scan drivers used includes a CMOS transistor.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.